Most sewer systems include one or more cleanout risers installed to enable quick and easy access for cleaning the sewer line for maintenance purposes. Modern sewer lines and fittings are most commonly constructed of PVC or ABS plastic. Sewer lines constructed of plastic offer many advantages over previously used materials; they are easy to install, cost effective, nontoxic and resistant to abrasion. However outdoor plastic cleanouts are subject to damage if struck by a mower blade, lawn tractor or other maintenance/road vehicle.
A large number of residential sewer cleanouts have been installed and placed into service without any mechanical protection whatsoever. Mechanical damage to unprotected sewer cleanouts is a significant cause of ingress and infiltration (I&I) into sewage treatment systems. Excess storm and groundwater entering the sewer system through I&I results in human health and environmental risk, robs the sewer system of its valuable capacity and puts a burden on operation and maintenance costs.
The vast majority of presently existing residential sewer cleanouts were installed without any protection from mechanical damage. Should an unprotected sewer cleanout be installed high relative to ground level the attached sewer system is susceptible to damage from passing vehicles. A cleanout mounted high relative to ground level also presents a trip hazard to passing pedestrians. Should an unprotected sewer cleanout be installed close to ground level there is susceptibility to damage from lawn maintenance equipment such as mowers, damage from passing vehicles being driven over the difficult to identify cleanout, as well as a susceptibility to the sewer cleanout becoming lost over time by virtue of being covered over by soil, gravel and grass.
One common method of protection for publicly accessible locations such as parking lots and sidewalks is to install a protective cast iron utility box over the plastic cleanout and then affix the cast iron utility box in place with a poured concrete slab reinforced with steel rebar. A brass or cast iron cover is affixed to the top of the cast iron utility box. However, cast iron utility boxes are expensive to purchase and their installation is time consuming and expensive requiring a significant amount of labor along with heavy equipment to install. Additionally access to the underground sewer system for maintenance requires a significant amount of labor to break apart the reinforced concrete slab and removal of the cast iron box.
Heretofore a variety of other approaches have been suggested for the protection of sewer cleanouts. One approach described in U.S. Pat. No. 8,844,559 to Dry discloses a method of protection consisting of a decorative fixture which provides visual notice of the cleanout. Unfortunately this method does not provide any mechanical protection for the cleanout. Dry's method is not applicable to a cleanout location near to driveways where moving vehicles are expected, is subject to damage from routine yard maintenance and other outdoor activities. Additionally this method is not suitable where such a method is aesthetically undesirable.
Another approach is that taken U.S. Pat. No. 5,769,565 to Martin et al. Martin recognized the importance of an improved cleanout protection device that incorporates a method of placing the sewer cleanout flush with the ground. While this strategy minimizes some exposure of the cleanout to damage from mower blades it suffers from several disadvantages. First, it is readily seen that the supporting skirt is composed entirely of thin ABS plastic which is easily distorted over time and may be exposed by any settling or erosion of the soil. Another disadvantage is that by virtue of being flush, the lawn and soil can be expected to readily conceal the device. Once lost the cleanout would be very difficult to locate in the event maintenance was needed to remove a sewer line clog. Yet another disadvantage is that vertical mechanical loading from heavy vehicles is supported by the underlying insubstantial plastic sewer lines and fittings.